Does a nitrogen-based plant food affect all bulbs this way or only Cala Lillies?
Nitrogen-Based Plant Food.
Nitrogen promotes green leafy growth in all plants. In excess, this growth will be at the expense of flowers. Obviously, plants need some nitrogen; it is the one major nutrient that passes through soil the quickest. Also, a fertilizer with lots of phosphorus and potassium can cause problems. A soil test is the best way to determine the nutrient needs of the soil in your garden. Without one, you are traveling blindly and at the mercy of fertilizer adds/product labels. Good cultural practices such as topdressing with 2 inches of compost, may be all that is necessary in healthy soil that isn't sandy.